Printing devices, such as printers for use with computers, facsimile machines and copiers, are typically sold with at least one, and in many cases, multiple ink cartridges. These cartridges include a housing that contains a reservoir of printing ink, either black or color, along with printer nozzles, which allow the ink to be transmitted to the intended medium and electrical contacts for communication between the printer and the cartridge.
Many such cartridges are intended to be disposable; when the cartridge is exhausted of ink, of course, printing becomes impossible. The emptied cartridge must be removed and a replacement cartridge must be substituted therefore to enable further printing. The disposable cartridge must then be disposed of in a proper fashion to reduce spillage of any remaining ink and to reduce any potential adverse environmental impact of the ink and other materials of the cartridge. Unless properly recycled, disposing of the empty cartridge increases the amount of garbage added to landfills.
In response to the negative environmental impact and cost disadvantages of disposable cartridges, refillable cartridges have been developed and welcomed by the marketplace. At present, these refillable cartridges may be refilled by the consumer by purchasing a refill kit including a syringe filled with ink and needle. In use, the cartridge is refilled by insertion of the needle into a refill port provided through the housing of the cartridge and emptying the syringe of ink into the reservoir of the cartridge. In practice, this is a less than ideal solution because this can be a messy procedure. Furthermore, the cartridge may have stopped functioning properly for reasons which are not related to the supply of ink and moreover, not diagnosable by the user.
Many cartridge manufacturers allow customers to return their empty cartridges to the manufacturer. The manufacturer then refills the cartridge and resells the refilled cartridge for a discounted price. Further, many companies obtain empty cartridges, refill them with ink and sell the refilled cartridges for a discounted price, creating competition and lower prices. Refilling an empty cartridge in this manner is a less expensive alternative, with a lesser amount of waste generated. There are numerous printer manufacturers, such as, for example, Hewlett Packard™, Lexmark™, Canon™, etc., and each manufactures multiple cartridges for the many printing devices. Each cartridge has a housing that contains a number of electrical contacts and print nozzles in various proprietary configurations, and is designed or configured such that it may only fit into a particular printing device and no other.
Generally, a printer cartridge comprises a print head that includes a number of microscopic chambers called nozzles. Ink flows from a reservoir in the cartridge into each of the nozzles by some combination of gravity and capillary action. Each nozzle has a small resistive element associated therewith that heats the ink, causing the ink to expand and be expelled from the nozzle. The ink flowing through the nozzle acts as a coolant. In use, the cartridges are properly inserted into a printing device which receives a signal in order to print on the medium. For example, a printer connected to a computer may receive a print signal from the computer, while a facsimile machine may receive a signal over a telephone line. The printing device converts that signal, depending on its driver program, and sends the appropriate control signal to the cartridge or, in the case of a color printing device, to multiple cartridges. Once the control signal is received, each cartridge transfers ink through its print nozzles as the medium passes beneath. When the control signal is complete, the printing device will have generated a document or drawing on the medium. Each use of the cartridge reduces the amount of toner or ink remaining in the cartridge. Depending on the size of the cartridge, a number of documents or drawings can be generated before the cartridge is empty or near empty. The larger the cartridge, the more ink it contains and the more documents can be printed. When empty, the cartridge needs to be replaced or reconditioned and/or refilled.
If the user operates a printer with an empty cartridge, the resistive heating elements in the cartridge may burn out (creating an open circuit) or draw high current (evidence of a short circuit). Because cartridges do fail in this manner, it is very advantageous for an inkjet cartridge re-manufacturer or the like to be able to test the electrical circuitry in a cartridge before refilling it, which reduces loss risks related to the time and cost it takes to perform the refilling step and the cost of the ink if the cartridge is defective and must be discarded. Furthermore, prior art testing devices that are currently available are either costly, complex, and require an AC line voltage power source or stand alone, handheld devices, that have a built in display, provide limited test results information, and require factory servicing to replace the battery power source.
A demand therefore exists for a device and method that allows a user to test a printer cartridge, that is inexpensive and is easily adaptable to various test applications depending on cartridge configuration, and that is convenient and reliable.